Enum ConstantExprKind 

pub enum ConstantExprKind {
    Literal(ConstantLiteral),
    Adt {
        kind: VariantKind,
        fields: Vec<ConstantFieldExpr>,
    },
    Array {
        fields: Vec<ConstantExpr>,
    },
    Tuple {
        fields: Vec<ConstantExpr>,
    },
    NamedGlobal(ItemRef),
    Borrow(ConstantExpr),
    RawBorrow {
        mutability: Mutability,
        arg: ConstantExpr,
    },
    Cast {
        source: ConstantExpr,
    },
    ConstRef {
        id: ParamConst,
    },
    FnDef(ItemRef),
    FnPtr(ItemRef),
    Memory(Vec<u8>),
    Todo(String),
}

The subset of [Expr] that corresponds to constants.

Variants

Literal(ConstantLiteral)

Adt

Fields

kind: VariantKind

fields: Vec<ConstantFieldExpr>

Array

Fields

fields: Vec<ConstantExpr>

Tuple

Fields

fields: Vec<ConstantExpr>

NamedGlobal(ItemRef)

A top-level or associated constant.

Remark: constants can have generic parameters. Example:

struct V<const N: usize, T> {
  x: [T; N],
}

impl<const N: usize, T> V<N, T> {
  const LEN: usize = N; // This has generics <N, T>
}

impl Foo for Bar {
  const C : usize = 32; // <-
}

If options.inline_anon_consts is false, this is also used for inline const blocks and advanced const generics expressions.

Borrow(ConstantExpr)

A shared reference to a static variable.

RawBorrow

A raw borrow (*const or *mut).

Fields

mutability: Mutability

arg: ConstantExpr

Cast

A cast <source> as <type>, <type> is stored as the type of the current constant expression. Currently, this is only used to represent lit as *mut T or lit as *const T, where lit is a usize literal.

Fields

source: ConstantExpr

ConstRef

Fields

id: ParamConst

FnDef(ItemRef)

A function definition, corresponding to a particular item. This is a ZST, unlike FnPtr.

FnPtr(ItemRef)

A function pointer. This is an actual pointer to that function.

Memory(Vec<u8>)

A blob of memory containing the byte representation of the value. This can occur when evaluating MIR constants. Interpreting this back to a structured value is left as an exercice to the consumer.

Todo(String)

Implementations

impl ConstantExprKind

pub fn decorate(self, ty: Ty, _span: Span) -> Decorated<Self>

Trait Implementations

impl Clone for ConstantExprKind

fn clone(&self) -> ConstantExprKind

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ConstantExprKind

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Hash for ConstantExprKind

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for ConstantExprKind

fn eq(&self, other: &ConstantExprKind) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for ConstantExprKind

impl StructuralPartialEq for ConstantExprKind